From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1FF60C282C7 for ; Tue, 29 Jan 2019 15:27:57 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E222721871 for ; Tue, 29 Jan 2019 15:27:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="D3CI8fVx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E222721871 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Sqx/hyCavQ/01qBnOMmTqeERH78qr35IK0ZYP+UyOFU=; b=D3CI8fVxnAIUuL U8bPevpldr/l/hkPsl8A0TmufU+pNYVBRgy3WiVfRNcEby0EEv2kjIYE6HMjaRCAwJMcDxAnDH4ho SD40PC6GFrt9O6Lrbm1u7YsnOD8SFBbqCpKqxSpTAOfQTMB3vFM+BD6gv8OmcbF/F6SCCNEB11IYG 1YI++lN1nuD5dA523Bs5yLRfpyQAnxAfsGXN6cX7S1bfnkWcyBZk7lcJ6Aq81K/gtMXLm6b/L7B2P 2LO6ODGVmJKVOxir5UDVLWrXaQDZv08kUe9Y+ithMwb8OwB8us8j4RTl3IOD/mZVsx6qB1DbUssvV UsP6fiomqUe05cMOclOA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1goVIp-0007as-2N; Tue, 29 Jan 2019 15:27:55 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1goVIl-0007Wd-4r for linux-arm-kernel@lists.infradead.org; Tue, 29 Jan 2019 15:27:52 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3F574A78; Tue, 29 Jan 2019 07:27:48 -0800 (PST) Received: from e107155-lin (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 913D23F557; Tue, 29 Jan 2019 07:27:45 -0800 (PST) Date: Tue, 29 Jan 2019 15:27:35 +0000 From: Sudeep Holla To: Quentin Perret Subject: Re: [PATCH 6/7] arm64: dts: juno: Add cpu dynamic-power-coefficient information Message-ID: <20190129152735.GA24772@e107155-lin> References: <20190128165522.31749-1-quentin.perret@arm.com> <20190128165522.31749-7-quentin.perret@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190128165522.31749-7-quentin.perret@arm.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190129_072751_204493_681E2041 X-CRM114-Status: GOOD ( 14.05 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, rjw@rjwysocki.net, nm@ti.com, lorenzo.pieralisi@arm.com, devicetree@vger.kernel.org, sboyd@kernel.org, viresh.kumar@linaro.org, mka@chromium.org, linux-pm@vger.kernel.org, liviu.dudau@arm.com, linux-kernel@vger.kernel.org, robh+dt@kernel.org, Sudeep Holla , dietmar.eggemann@arm.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Jan 28, 2019 at 04:55:21PM +0000, Quentin Perret wrote: > From: Dietmar Eggemann > > A CPUfreq driver, like the scpi driver used on Juno boards, which > provide the Energy Model with power cost information via the PM_OPP > of_dev_pm_opp_get_cpu_power() function, do need the > dynamic-power-coefficient (C) in the device tree. > > Method used to obtain the C value: > C is computed by measuring energy (E) consumption of a frequency domain > (FD) over a 10s runtime (t) sysbench workload running at each Operating > Performance Point (OPP) affine to 1 or 2 CPUs of that FD while the other > CPUs of the system are hotplugged out. > By definition all CPUs of a FD have the the same micro-architecture. An > OPP is characterized by a certain frequency (f) and voltage (V) value. > The corresponding power values (P) are calculated by dividing the delta > of the E values between the runs with 2 and 1 CPUs by t. > > With n data tuples (P, f, V), n equal to number of OPPs for this > frequency domain, we can solve C by: > > P =3D Pstat + Pdyn > > P =3D Pstat + CV=B2f > > Cx =3D (Px - P1)/(Vx=B2fx - V1=B2f1) with x =3D {2, ..., n} > > The C value is the arithmetic mean out of {C2, ..., Cn}. > > Since DVFS is broken on Juno r1, no dynamic-power-coefficient > information has been added to its dts file. > Since the binding for "dynamic-power-coefficient" property already exist, and I don't see any dependency for this and the next patch(TC2) on this series, I will apply them. Please shout if for any reason that's not true. -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel